package com.example.administrator.musicplayer;

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.media.MediaPlayer;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.widget.Toast;

import com.example.administrator.musicplayer.data.MusicList;

import java.io.IOException;

/**
 * Created by Administrator on 2017/10/26.
 */

public class MusicService extends Service {
    // 播放控制命令，标识操作
    public static final int COMMAND_UNKNOWN = -1;
    public static final int COMMAND_PLAY = 0;
    public static final int COMMAND_PAUSE = 1;
    public static final int COMMAND_STOP = 2;
    public static final int COMMAND_RESUME = 3;
    public static final int COMMAND_PREVIOUS = 4;
    public static final int COMMAND_NEXT = 5;
    public static final int COMMAND_CHECK_IS_PLAYING = 6;
    public static final int COMMAND_SEEK_TO = 7;
    // 播放器状态̬
    public static final int STATUS_PLAYING = 0;
    public static final int STATUS_PAUSED = 1;
    public static final int STATUS_STOPPED = 2;
    public static final int STATUS_COMPLETED = 3;
    // 广播标志
    public static final String BROADCAST_MUSICSERVICE_CONTROL = "MusicService.ACTION_CONTROL";
    public static final String BROADCAST_MUSICSERVICE_UPDATE_STATUS = "MusicService.ACTION_UPDATE";

    private int number = 0;
    private int status;

    private MediaPlayer player = new MediaPlayer();
    // 广播接收器
    private CommandReceiver receiver;

    @Override
    public void onCreate() {
        super.onCreate();
        //帮顶广播接收器，可以接收广播
        bindCommandReceiver();
        status = MusicService.STATUS_STOPPED;

    }

    @Override
    public void onDestroy() {
        if (player != null){
            player.release();
        }
        super.onDestroy();
    }

    @Nullable
    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    //内部类，接收广播命令并执行操作
    class CommandReceiver extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {
            int command = intent.getIntExtra("command", COMMAND_UNKNOWN);
            //执行命令
            switch (command) {
                case COMMAND_PLAY:
                    number = intent.getIntExtra("number", 0);
                    play(number);
                    break;
                case COMMAND_PREVIOUS:
                    moveNumberToPrevious();
                    break;
                case COMMAND_NEXT:
                    moveNumberToNext();
                    break;
                case COMMAND_PAUSE:
                    pause();
                    break;
                case COMMAND_STOP:
                    stop();
                    break;
                case COMMAND_RESUME:
                    resume();
                    break;
                case COMMAND_CHECK_IS_PLAYING:
                    if (player != null && player.isPlaying()) {
                        sendBroadcastOnStatusChanged(MusicService.STATUS_PLAYING);
                    }
                    break;
                case COMMAND_UNKNOWN:
                default:
                    break;
            }

        }
    }

    //绑定广播接收器
    private void bindCommandReceiver(){
        receiver = new CommandReceiver();
        IntentFilter filter = new IntentFilter(BROADCAST_MUSICSERVICE_CONTROL);
        registerReceiver(receiver, filter);

    }

    //发送广播，状态发生改变
    private void sendBroadcastOnStatusChanged(int status){
        Intent intent = new Intent(BROADCAST_MUSICSERVICE_UPDATE_STATUS);
        intent.putExtra("status", status);
        sendBroadcast(intent);
    }
    //播放结束的监听器
    MediaPlayer.OnCompletionListener completionListener = new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mp) {
            if (player.isLooping()){
                replay();
            }
            else {
                sendBroadcastOnStatusChanged(MusicService.STATUS_COMPLETED);
            }
        }
    };


    private void load(int number){
        try {
            player.reset();
            player.setDataSource(MusicList.getMusicList().get(number).getMusicPath());
            player.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }
        player.setOnCompletionListener(completionListener);
    }

  //播放音乐
    private void play(int number) {
        // ֹֹͣͣ停止当前播放
        if (player != null && player.isPlaying()) {
            player.stop();
        }
        load(number);
        player.start();
        status = MusicService.STATUS_PLAYING;
        sendBroadcastOnStatusChanged(MusicService.STATUS_PLAYING);
    }

    //暂停音乐
    private void pause() {
        if (player.isPlaying()) {
            player.pause();
            status = MusicService.STATUS_PAUSED;
            sendBroadcastOnStatusChanged(MusicService.STATUS_PAUSED);
        }
    }

    //停止播放
    private void stop() {
        if (status != MusicService.STATUS_STOPPED) {
            player.stop();
            status = MusicService.STATUS_STOPPED;
            sendBroadcastOnStatusChanged(MusicService.STATUS_STOPPED);
        }
    }

    //回复播放
    private void resume() {
        player.start();
        status = MusicService.STATUS_PLAYING;
        sendBroadcastOnStatusChanged(MusicService.STATUS_PLAYING);
    }

    //重新播放
    private void replay() {
        player.start();
        status = MusicService.STATUS_PLAYING;
        sendBroadcastOnStatusChanged(MusicService.STATUS_PLAYING);
    }

    //上一首歌曲
    private void moveNumberToPrevious() {
        // 判断是否到达列表顶端
        if (number == 0) {
            Toast.makeText(MusicService.this,"已达到列表顶端",Toast.LENGTH_SHORT).show();
        } else {
            --number;
            play(number);
        }
    }
   //下一首歌曲
    private void moveNumberToNext() {
        // 判断是否到达列表底端
        if ((number ) == MusicList.getMusicList().size()-1) {
            Toast.makeText(MusicService.this,"已达到列表底端",Toast.LENGTH_SHORT).show();
        } else {
            ++number;
            play(number);
        }
    }




}
